Heat exchanger cores are commonly formed from a plurality of thin, substantially flat tubes, stacked upon one another in spaced relation, which extend between a pair of spaced-apart manifolds. The manifolds are often simply constructed from pipe, suitably perforated to receive the flat tubes. Exemplary of this construction is the heat exchanger described in U.S. Pat. No. 5,183,103 (Tokutake), issued Feb. 2, 1993.
For the purpose of mounting, i.e., within the engine compartment of a vehicle or the like, heat exchanger cores of the type comprising perforated pipe manifolds, it is known to braze a mounting bracket to the manifold. The mounting bracket usually includes a tab or flange adapted to be secured to the vehicle frame. Usually, the mounting bracket is provided with a portion which is capable of resiliently engaging the exterior of the manifold to keep the mounting bracket in place during the brazing process, so as to avoid the need for auxiliary clamping tools, which can add to cost and can absorb heat in a brazing oven, resulting in poor quality brazed joints. The mounting brackets taught in U.S. Pat. No. 5,069,275 (Suzuki et al.), issued Dec. 3, 1991, are exemplary of this construction.
A difficulty with the pipe manifold type of heat exchanger cores, however, is that the pipe manifolds have to be made quite strong to support the mounting brackets, so this makes them heavy and expensive to manufacture.
Another type of heat exchanger cores uses plate pairs to define the heat exchanger passages. The plates are formed of back-to-back dish-shaped plates, each plate having a central portion, a pair of spaced-apart bosses and a peripheral flange. The plates thus disposed in pairs have the peripheral flanges of each plate in the pair connected to one another to form a fluid passage between the central portions, and the plate pairs are disposed in stacked relation, with the bosses in adjacent pairs having through holes therein, so that when the bosses are joined to one another, they form a manifold to permit the flow of fluid through the pairs. Exemplary of this construction is the heat exchanger core described in U.S. Pat. No. 5,964,282 (Seiler et al.), issued Oct. 12, 1999.
Characteristic of the plate pair type of heat exchanger cores used in the past is that special heavier gauge plates are usually required to be joined to the fluid carrying plate pairs in order to permit suitable mounting brackets to be attached to the cores. This again increases the number of components required and thus the cost of the heat exchangers.